Residential Brownfield Developments up to 1.5ha in England to be Exempt from Biodiversity Net Gain (BNG)

Within the 2026 Autumn Budget it was announced that residential brownfield developments on sites up to 1.5 hectares in England will be exempt from biodiversity net gain (BNG).

An implementation date has not been set. The government’s consultation response and impact assessment will follow.

BNG normally requires development within its scope to leave wildlife habitats with at least 10% more biodiversity value than before, using a system that bizarrely takes no account of soil and the potentially rich bio-diversity therein. Developers can deliver that improvement either on their site or off-site.

This is intended to intended to reduce the cost of building homes on previously developed land. The question we would ask is:

“Which is the more costly, time consuming and bewildering, the implementation of some small measures to protect nature, and our future as a species on this planet, or the need to employ another consultant to tackle to complexities of the BNG matrix?”

Conservation groups are concerned about the cumulative effect of exemptions. On 7 May, Matt Browne of The Wildlife Trusts and Philip Box of Wildlife and Countryside Link wrote: “BNG cannot function as a ‘win-win’ policy for nature and development if it is riddled with loopholes.”